In order to improve fuel consumption by shortening the warm-up time at a restart of an engine, and to reduce wear of a transmission by securing a heat-retaining property (lubricity) of engine oil, an art has already been known, as disclosed in JP2013-119384A, related to an engine encapsulating structure which improves the engine heat-retaining property by covering the engine at least from above and the side with a cover.
JP2013-119384A discloses a structure in which an upper surface cover 111 covers engine from above, a frame shroud is disposed forward of the engine (e.g., see FIG. 3 of JP2013-119384A), and a front end of the upper surface cover 111 is placed on an upper side (carrier 13) of the shroud. A frame shutter holding member (cooling duct 25) is disposed forward of the shroud and rearward of a bumper face, and the shutter holding member is provided with a plurality of grille shutters which enable a traveling air introducing opening of the bumper face to open and close (see FIGS. 1 and 3 of JP2013-119384A).
However, according to this structure, since the frame shutter holding member is disposed so as to be separated forward from the shroud, heat easily escapes through a gap in the vehicle longitudinal directions between the shutter holding member and the shroud. Moreover, since the shutter holding member is not generally formed as strong as the shroud which is structured to support a radiator and the front end of the upper surface cover (upper lid part), it tends to be formed in a thinner frame shape than the shroud, resulting in poor heat retention performance. Therefore, there is room for improvement related to heat retention efficiency of the structure forward of the engine.
Further, since this structure is provided with the frame shutter holding member forward of the engine in addition to the shroud, the number of components may increase to push up the cost and the weight.